package 面向对象.作业;

public class Circle {
    public double r;

    public Circle() {
    }

    public Circle(double r) {
        this.r = r;
    }
    public void showArea(){//打印圆的面积
        System.out.println("圆的面积"+3.14*r*r);
    }
    public void showPerimeter(){
        System.out.println("圆的周长"+r*2*3.14);
    }
}
